DeVilbiss GTI-620S Service Manual
SERVICE BULLETIN
SB-2-473-N
Replaces SB-2-473-M
Repair Kit KK-5058-2
GTI-620S COMPLIANT HIGH VOLUME LOW PRESSURE
SUCTION FEED SPRAY GUN
IMPORTANT: Before using this equipment,
read all safety precautions and instructions.
Keep for future use.
DESCRIPTION
These compliant high volume low pressure
suction feed GTI
apply a wide variety of finishing materials.
The guns were manufactured to provide
maximum transfer efficiency by limiting air
cap pressure to 10 psi (complies with rules
issued by SCAQMD and other air quality
authorities).
These guns will produce approximately 10
psi cap pressure at 30 psi gun inlet pressure. Air cap test kits are available (see
ACCESSORIES) which can be utilized to set
the exact air cap pressure. Air consumption
for the GTI 600S (#100 cap) is 16 SCFM at
10 psi air cap pressure. Air consumption for
the GTI-620S (#2000 cap) is 15.5 SCFM at 10
psi air cap pressure.
These guns include 300 series
stainless steel fluid tips and
needles. Guns may be used with
chlorinated solvent materials. See
page 2 for additional warnings.
Important: These guns may be used with
most common coating and finishing materials. They are designed for use with mildly
corrosive and non-abrasive materials. If
used with other high corrosive or abrasive
materials, it must be expected that frequent
and thorough cleaning will be required and
the necessity for replacement of parts will
be increased.
INSTALLATION
For maximum transfer efficiency, do not use
more pressure than is necessary to atomize
the material being applied.
1. Connect the gun to a clean, moisture
and oil free air supply using a hose
size of at least 5/16" I.D. hose. Do not
use 1/4" I.D. hose (25' x 1/4" hose at 18
CFM has a pressure loss of 25 psi. 25'
x 5/16" hose at 18 CFM has a pressure
loss of 8 psi).
Depending on hose length, larger
I.D. hose may be required. Install an
HAV-501 air gauge at the gun handle
and air cap test kit over tip. When
gun is triggered on, adjust regulated pressure to desired setting to
®
guns are designed to
Note
Note
provide a maximum of 10 psi at the
air cap. Do not use more pressure
than is necessary to atomize the material being applied. Excess pressure
will create additional overspray and
reduce transfer efficiency.
Note
If quick connects are required, use
only high flow quick connects approved for HVLP use such as DeVilbiss HC-4419 and HC-4719. Other
types will not flow enough air for
proper gun operation.
Note
If an air adjusting valve is used at the
gun inlet, use DeVilbiss Model HAV500 or HAV-501 or HAV-511. Some
competitive adjusting valves have
significant pressure drop that can
adversely affect spray performance.
Models HAV-500 and HAV-501 have
minimal pressure drop, which is
important for HVLP spraying.
2. Attach the suction feed cup to the material inlet.
Note
Protective coating and rust inhibitors have been used to keep the
gun in good condition prior to
shipment. Before using the gun,
flush it with solvents so that these
materials will be removed from
fluid passages.
OPERATION
Mix, prepare and strain the material to be
sprayed according to the paint maufacturer's
instructions.
Strain material through a 60 or 90 mesh
screen.
1. Fill the suction feed cup with the material. Do not overfill. Make sure that the
cup lid vent hole is clear.
2. Open the spreader adjustment valve
(10) (Fan) by turning the valve stem
counterclockwise.
3. Open fluid adjusting screw (17) by
turning counterclockwise.
4. Turn on air supply and set gun inlet
pressure to lowest recommended
pressure for material being sprayed.
Spray a test area. Air pressure and
paint flow should be adjusted to provide a uniform dispersion of atomized
paint throughout the pattern. Keep
air pressure as low as possible to
minimize bounce-back and overspray.
Excessive fluid flow will result in heavy
center spray patterns. Inadequate flows
may cause the patterrn to split. See
TROUBLESHOOTING, Page 5, if any
problems occur. If finer atomization is
required, increase gun inlet pressure.
If a reduced fluid flow rate is required,
turn fluid adjusting screw (17) clockwise
until desired fluid flow is obtained.
See Spray Gun Guide, SB-2-001 latest
revision, for details concerning setup of
spray guns.
PREVENTIVE MAINTENANCE
To clean air cap and fluid tip, brush exterior
with a stiff bristle brush. If necessary to clean
cap holes, use a broom straw or toothpick
if possible. If a wire or hard instrument is
used, extreme care must be used to prevent
scratching or burring of the holes which will
cauase a distorted spray pattern.
To clean fluid passages, remove excess
material from cup, then flush with a suitable solvent. Wipe gun exterior with a
solvent dampened cloth. Never completely
immerse in solvent as this is detrimental to
the lubricants and packings.
Note
When replacing the fluid tip or
fluid needle, replace both at the
same time. Using worn parts can
cause fluid leakage. See Chart 2.
Also, replace the needle packing
at this time. Lightly lubricate the
threads of the fluid tip before reassembling. Torque to 15-20 ft. lbs.
Do not overtighten the fluid tip.
To prevent damage to fluid tip (5) or
fluid needle (11), be sure to either
1) pull the trigger and hold while
tightening or loosening the fluid
tip, or 2) remove fluid needle adjusting screw (17) to relieve spring
pressure against needle collar.
Page 2 SB-2-473-N
SAFETY PRECAUTIONS
This manual contains information that is important for you to know and understand. This information relates to USER SAFETY and
PREVENTING EQUIPMENT PROBLEMS. To help you recognize this information, we use the following symbols. Please pay particular
attention to these sections.
NOTE
Important information that tells how to
Important safety information - A hazard
that may cause serious injury or loss
of life.
prevent damage to equipment, or how
to avoid a situation that may cause
minor injury.
The following hazards may occur during the normal use of this equipment.
Please read the following chart before using this equipment.
HAZARD CAUSE SAFEGUARDS
Fire
Solvent Spray
Inhaling Toxic Substances
Explosion Hazard Incompatible Materials
General Safety
Cumulative Trauma
Disorders ("CTD's")
CTD's, or musculoskeletal
disorders, involve damage
to the hands, wrists, elbows,
shoulders, neck, and back.
Carpal tunnel syndrome
and tendonitis (such as
tennis elbow or rotator cuff
syndrome) are examples of
CTD's.
Solvent and coatings can be highly
flammable or combustible especially when
sprayed.
During use and while cleaning and flushing,
solvents can be forcefully expelled from
fluid and air passages. Some solvents can
cause eye injury.
Certain materials may be harmful if inhaled,
or if there is contact with the skin.
Halogenated hydrocarbon solvents - for
example; methylene chloride and 1,1,1,
- Trichloroethane are not chemically
compatible with the aluminum that might
be used in many system components. The
chemical reaction caused by these solvents
reacting with aluminum can become violent
and lead to an equipment explosion.
Improper operation or maintenance of
equipment.
Use of hand tools may cause cumulative
trauma disorders ("CTD's").
CTD's, when using hand tools, tend to affect
the upper extremities. Factors which may
increase the risk of developing a CTD include:
1. High frequency of the activity.
2. Excessive force, such as gripping,
pinching, or pressing with the hands and
fingers.
3. Extreme or awkward finger, wrist, or arm
positions.
4. Excessive duration of the activity.
5. Tool vibration.
6. Repeated pressure on a body part.
7. Working in cold temperatures.
CTD's can also be caused by such activities
as sewing, golf, tennis, and bowling, to
name a few.
Adequate exhaust must be provided to keep air free of
accumulations of flammable vapors.
Smoking must never be allowed in the spray area.
Fire extinguishing equipment must be present in the spray area.
Wear eye protection.
Follow the requirements of the Material Safety Data Sheet
supplied by your coating material manufacturer.
Adequate exhaust must be provided to keep the air free of
accumulations of toxic materials.
Use a mask or respirator whenever there is a chance of inhaling
sprayed materials. The mask must be compatible with the material
being sprayed and its concentration. Equipment must be as prescribed by an industrial hygienist or safety expert, and be NIOSH
approved.
Guns with stainless steel internal passageways may be used with
these solvents. However, aluminum is widely used in other spray
application equipment - such as material pumps, regulators,
valves, and cups. Check all equipment items before use and make
sure they can also be used safely with these solvents. Read the
label or data sheet for the material you intend to spray. If in doubt
as to whether or not a coating or cleaning material is compatible,
contact your material supplier.
Operators should be given adequate training in the safe use
and maintenance of the equipment (in accordance with the
requirements of NFPA-33, Chapter 15). Users must comply with
all local and national codes of practice and insurance company
requirements governing ventilation, fire precautions, operation,
maintenance, and housekeeping. These are OSHA Sections
1910.94 and 1910.107 and NFPA-33.
Pain, tingling, or numbness in the shoulder, forearm, wrist,
hands, or fingers, especially during the night, may be early
symptoms of a CTD. Do not ignore them. Should you experience
any such symptoms, see a physician immediately. Other early
symptoms may include vague discomfort in the hand, loss of
manual dexterity, and nonspecific pain in the arm. Ignoring early
symptoms and continued repetitive use of the arm, wrist, and
hand can lead to serious disability. Risk is reduced by avoiding or
lessening factors 1-7.
Information that you should pay special
attention to.
CA PROP
65
PROP 65 WARNING
WARNING: This product contains
chemicals known to the State of
California to cause cancer and birth
defects or other reproductive harm.
SPRAY GUN LUBRICATION
Daily, apply a drop of SSL-10* spray gun
lube at trigger bearing stud (28) and the
stem of air valve (20) where it enters air valve
assembly. The shank of fluid needle (11)
where it enters packing nut (9) should also
be oiled. Fluid needle packing (8) should be
lubricated periodically. Make sure baffle (6)
and retaining ring (3) threads are clean and
free of foreign matter. Before assembling
retaining ring to baffle, clean the threads
thoroughly, then add two drops of SSL-10
spray gun lube to threads. Fluid needle
spring (14) and air valve spring (19) should
be coated with a very light grease, making
sure that any excess grease will not clog the
air passages. For best results, lubricate the
points indicated, daily.
* Not for air tools or high RPM equipment.
A. Trigger Points
B. Packing
C. Adjusting Knobs
D. Baffle Threads
E. Air Valve Cartridge
A
C
D
B
E
PARTS REPLACEMENT
Figure 1 Air Cap
Air Cap No.
XXX
HVLP: 30 PSI
MAX. INLET
Maximum air pressure required to
assure compliance of 10 PSI Max.
Cap Pressure - this reading must
be taken at the spray gun handle
inlet fitting.
Chart 1
No on Air Cap Air Cap with Ring
Order (Ref. No. 4)
100 GTI-407-100
2000 GTI-407-2000
Chart 2
Fluid Tips
Fluid Tip Size I.D.
Tip No. In. mm
GTI-213-18 0.070 1.8
GTI-213-20 0.078 2.0
GTI-213-22 0.086 2.2
JGA-4035 Packing Replacement
Instructions
SB-2-473-N Page 3
11. After each adjustment, pull needle
open and observe needle closure.
12. If needle snaps shut, continue adjusting nut until there is evidence of
needle bind or slow closing.
13. Back off packing nut 1/12 turn to the
point where needle snaps shut. Packing nut must remain tight enough to
prevent loosening by hand.
14. Pull needle several times to verify
needle snaps shut and check packing
nut for looseness.
GTI-33 Baffle Seal Replacement
1. Remove Fluid Tip (5).
2. Remove Baffle (6).
3. Remove Seal (7) from baffle.
NOTE
The seal is designed to be a tight
fit on the baffle. The seal should
be able to be removed using your
fingers. If you are unable to remove
the seal using your fingers, insert
a small screwdriver between the
outer lip and the back of the baffle
and pry the seal off.
ANGLED SIDE
SEAL
THICK SIDE
Pry here if
necessary
BAFFLE
PARTS REPLACEMENT
FLUID INLET GASKET (32)
REPLACEMENT INSTUCTIONS
1. Remove fluid inlet adapter (34) with
appropriate wrench.
2. Clean Loctite from gun body inlet
threads and seal area.
3. Place gasket (32) squarely onto the fluid
inlet adapter and push it down until it
is flat against the shoulder.
4. Use medium strength thread sealant
(i.e. Devcon 2242 blue, or equal) on
threads before installing fluid inlet
adapter.
5. Torque fluid inlet adapter to 20-25 ft.
lbs. and tighten locknut.
Needle
Gun Body
1. Remove adjusting knob and needle
spring from gun.
2. Partially withdraw needle from gun
body.
3. Loosen packing nut and remove.
4. Remove old packing.
5. Assemble packing nut to needle.
6. Assemble packing in order shown to
needle.
7. Insert needle all the way into gun
body seating in tip.
8. Install needle spring and adjusting
knob.
9. Thread packing nut into gun body.
10. Tighten packing nut in equal increments – no more than 1/6 turn
at a time.
Packing
(3 pieces)
Packing
Nut
4. Assemble seal to baffle with angled side
up as shown above. NOTE: The seal
should be a tight fit on the baffle. If it is
a loose fit on the baffle, assure that it is
assembled with the angled side up.
5. Install baffle on gun.
6. Install fluid tip (5) and tighten to
15-20 ft-lbs.
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